ACS is a rather unfortunately named feature. We now have several "sources" (no pun intended) of naming-related confusion for a few different Satellite features:

1. An Alternate Content Source, defined here, has nothing to do with a host's "content source."
2. A host's "content source" refers to the Capsule (downstream name) or Smart Proxy with Content (upstream name) from which the host gets its content. There is a "Change Content Source" feature which refers to this content source, but again, has nothing to do with ACSs.
3. Before the Change Content Source feature launched, a host's content source was referred to as its "Registered-through Capsule" or "Registered-through Smart Proxy." This nomenclature still exists in the UI on the legacy content host details page > "Registered Through."

I think notes should be added here and also in the Capsule documentation (or Change Content Source documentation?) that help differentiate between Alternate Content Sources and Content Sources.

Reported by: rhn-engineering-jlenz

https://access.redhat.com/documentation/en-us/red_hat_satellite/6.13/html/managing_content/managing_alternate_content_sources_content-management#annotations:7ed3724f-2715-4cd8-94d2-2f48c5d61743